[U-Boot] [PATCH v1 01/12] rockchip: define SUPPORT_SPL and SPL config in RK3288 config

[hl <hl@rock-chips.com>]

Hi Simon,

On 26/10/15 12:12, Simon Glass wrote:
>
> Hi,
>
> On Oct 22, 2015 7:22 PM, "hl" <hl@rock-chips.com 
> <mailto:hl@rock-chips.com>> wrote:
> >
> > Hi Simon,
> >
> >
> > On 23/10/15 09:04, Simon Glass wrote:
> >>
> >> Hi Eddie,
> >>
> >> On 22 October 2015 at 18:54, Eddie Cai <eddie.cai@rock-chips.com 
> <mailto:eddie.cai@rock-chips.com>> wrote:
> >>>
> >>> Hi Simon
> >>>
> >>> 2015-10-23 0:30 GMT+08:00 Simon Glass <sjg@chromium.org 
> <mailto:sjg@chromium.org>>:
> >>>>
> >>>> Hi Eddie,
> >>>>
> >>>> On 22 October 2015 at 10:01, Eddie Cai <eddie.cai@rock-chips.com 
> <mailto:eddie.cai@rock-chips.com>> wrote:
> >>>>>
> >>>>> Hi Simon
> >>>>>
> >>>>> 2015-10-22 22:07 GMT+08:00 Simon Glass <sjg@chromium.org 
> <mailto:sjg@chromium.org>>:
> >>>>>>
> >>>>>> Hi Lin,
> >>>>>>
> >>>>>> On 20 October 2015 at 20:37, Lin Huang <hl@rock-chips.com 
> <mailto:hl@rock-chips.com>> wrote:
> >>>>>>>
> >>>>>>> it may not use SPL in other rockchip SOC, so move SUPPORT_SPL and
> >>>>>>> SPL config to rk3288 configuration.
> >>>>>>>
> >>>>>>> Signed-off-by: Lin Huang <hl@rock-chips.com 
> <mailto:hl@rock-chips.com>>
> >>>>>>> ---
> >>>>>>> Changes in v1: None
> >>>>>>>
> >>>>>>>   arch/arm/Kconfig               | 2 --
> >>>>>>>   arch/arm/mach-rockchip/Kconfig | 2 ++
> >>>>>>>   2 files changed, 2 insertions(+), 2 deletions(-)
> >>>>>>>
> >>>>>>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> >>>>>>> index 194fb7b..40fa741 100644
> >>>>>>> --- a/arch/arm/Kconfig
> >>>>>>> +++ b/arch/arm/Kconfig
> >>>>>>> @@ -831,8 +831,6 @@ config TARGET_STM32F429_DISCOVERY
> >>>>>>>
> >>>>>>>   config ARCH_ROCKCHIP
> >>>>>>>          bool "Support Rockchip SoCs"
> >>>>>>> -       select SUPPORT_SPL
> >>>>>>> -       select SPL
> >>>>>>>          select OF_CONTROL
> >>>>>>>          select CPU_V7
> >>>>>>>          select DM
> >>>>>>> diff --git a/arch/arm/mach-rockchip/Kconfig
> >>>>>>> b/arch/arm/mach-rockchip/Kconfig
> >>>>>>> index ab50f4e..15cd380 100644
> >>>>>>> --- a/arch/arm/mach-rockchip/Kconfig
> >>>>>>> +++ b/arch/arm/mach-rockchip/Kconfig
> >>>>>>> @@ -2,6 +2,8 @@ if ARCH_ROCKCHIP
> >>>>>>>
> >>>>>>>   config ROCKCHIP_RK3288
> >>>>>>>          bool "Support Rockchip RK3288"
> >>>>>>> +       select SUPPORT_SPL
> >>>>>>> +       select SPL
> >>>>>>>          help
> >>>>>>>            The Rockchip RK3288 is a ARM-based SoC with a quad-core
> >>>>>>> Cortex-A17
> >>>>>>>            including NEON and GPU, 1MB L2 cache, Mali-T7 
> graphics, two
> >>>>>>> --
> >>>>>>> 1.9.1
> >>>>>>>
> >>>>>> We should avoid little binary blobs for booting the chip. I 
> think we
> >>>>>> can live with this as a stepping stone to having a proper SPL, but
> >>>>>> what is the plan for a proper SPL in U-Boot?
> >>>>>
> >>>>> RK3036 have only 8k sram. 4k used by boot rom. The ddr 
> initialize code
> >>>>> is
> >>>>> almost 4k. So i don't think we can do SPL.
> >>>>
> >>>> How does U-Boot get loaded in this case? Does it use ROM code? If so
> >>>
> >>> Yes, it use boot rom code to load U-Boot
> >>>>
> >>>> then I think we should create an SPL that handles the DDR init and
> >>>> then returns to the ROM code for loading U-Boot. Also we should
> >>>> document how this works in the README.
> >>>
> >>> It is a good news you agree we can return to boot rom from SPL. Do 
> you know
> >>> what size of sram a smallest SPL need?
> >>
> >> Exynos does something a little similar - it has a jump table of ROM
> >> routines that SPL can call.
> >>
> >> You can essentially write your own code for SPL. I very much hope you
> >> can use start.S and cro0.S, but these add up to a tiny amount of code
> >> so should not cause problems. You should be able to put all of your
> >> code into your implementation of board_init_f(), using most of the 4KB
> >> available. U-Boot's SPL framework does add some overhead, but if you
> >> leave out the board_init_r() implementation this is very small.
> >>
> >> If you do get stuck and find the size if over 4KB we should discuss it
> >> and see what can be done.
> >
> >
> >      Okay, i will reference exynos to see how to do,  thank you.
> >
>
> One last point...  U-Boot is written in C so as much as possible of 
> this should be C, rather than assembler.
>

         Thank you for pointing that. I try to get a clean SPL(only 
timer and uart driver), and it can work now,
          it take about 600 bytes, i will start to port ddr driver.
>
> Regards,
> Simon
>

-- 
Lin Huang